Firing pin mechanism for hand grenades



NOV. 10, 1959 K. suN 2,911,913

FIRING PIN MECHANISM FOR HAND GRENADES Filed Nov. 28, 1956 3Sheets-Sheet l Nov. 10, 1959 K. H. SUNDEN FIRING PIN MECHANISM FOR HANDGRENADES 3 Sheets-Sheet 2 Filed Nov. 28, 1956 Nov. 10, 1959 K. H. SUNDEN2,911,913

FIRING PIN MECHANISM FOR HAND GRENADES Filed Nov. 28, 1956 sSheets-Sheet s United States aten 2,911,913 FIRING PIN MECHANISM FORHAND GRENADES :Karl Henrik Sunden, Lindesberg, Sweden ApplicationNovember 28, 1956, Serial No. 624,893 I 1 Claim. (Cl. 102-64) Thepresent invention relates to a firing pin mechanism for hand grenadesand similar weapons, in which the firing pin, which is arranged tostrike the primer of a detonator or the like, is disposed on a hammerpivotally mounted in the frame of the mechanism, said hammer beingretained in a cocked position by a handle or the like serving as asafety means for the thrower, which handle is moved aside, when thegrenade is thrown, through the action of the pivoting motion of thehammer, so that the firing pin can strike the primer. The essentiallycharacteristic feature of the mechanism is that the hammer is providedwith one or more extensions which are arranged to engage with the handleboth when the grenade is secured and when it is thrown, so as to preventthe firing pin from engaging the handle, and thus ensure that the firingpin is not deformed when it strikes the primer.

For a better understanding of the invention two preferred embodimentsthereof as applied to a firing pin mechanism for hand grenades will nowbe described by way of example, with reference to the accompanyingdrawings:

In the drawings:

Fig. 1 is a longitudinal section of the mechanism according to oneembodiment, disposed on a hand grenade, hammer 6 adjacent pin 3 beingpartly broken away to show the engagement of spring end 10 therewith;

Fig. 2 is a lateral view, partly in section, of the mechanism accordingto the other embodiment, also disposed on a hand grenade; and

Figs. 3, 4 and 5 are respectively lateral, top and front views of thehammer with the firing pin.

Reference numeral 1 designates the hand grenade proper which is providedwith the firing pin mechanism 2 whose firing pin 3 is arranged to strikethe primer 5 of the detonator 4 when the grenade is thrown, so that saidprimer is ignited in order to make the grenade 1 explode.

The firing pin 3 preferably is an integral part of a hammer 6 which ispivotally mounted on a shaft 8 included in the frame 7 of the mechanism.A firing pin spring 9 cooperates with the hammer 6. That springconsists, in the embodiment shown, of a helical spring mounted on theshaft 8 and having one of its ends 10 engaging with the hammer 6, whileits other end 11 engages with the frame 7.

The hammer 6 is retained in its secured position by the handle 12 or asimilar securing means, the end 13 of which is of hook shape and engageswith a projection 14 or the like in the frame 7. During transport thehandle 12 is retained in position by a safety needle 15. The safetyneedle passes with one of its two legs 15 through holes 16 both in thehandle 12 and in the frame 7, its other leg 15" overlying handle 12. Theframe 7 is also provided with holes 17 which are covered by the sideportions 18 of the handle 12 in the illustrated position, wherein thegrenade is secured by the handle 12. When the handle 12 is swung to theposition in which the holes 17 are uncovered, a steel wire can beintroduced into the holes 17 to lock the cock 6, whereupon the handle 12can be removed without the mechanism being released, which is ofimportance in order that the grenade may be armed or assembled, andinspected.

As appears from Figs. 3, 4 and 5, the hammer 6 and the firing pinmounted adjacent it preferably are made of a single piece of sheetmetal. That piece consists of a plane portion 20, which is parallel tothe shaft 8, and a pair of legs or extensions 21 bent at right angles tothe plane portion 20. Between the legs 21 the firing pin 3 projects fromthe plane portion 20, the legs 21 extending outside the point of thefiring pin 3, so that said point is protected during its movementtowards the primer 5. In order that the legs 21 may not prevent thefiring pin 3 from striking the rimer 5, the legs are spaced a distancefrom each other which is greater than the width of the detonator 4 atthe primer 5. The legs 21 preferably are spaced such a distance fromeach other as to be guided by the parallel upstanding sides of the frame7.

The legs 21 have portions 22 which are provided with oppositely locatedholes 23 for rotatably mounting the hammer 6 on the shaft 8. Theportions 22 are shaped as cams 24 outside the holes 23. The outer edgesof these cams extend above the upper edges 25 of the frame 7 when thefiring pin is in the released or fired position, so that the handle 12cannot be secured to the mechanism in that position. On one side of theearns 24 the portions 22 are further shaped to form notches 26 withwhich a steel wire, when placed through the holes 17, is adapted toengage when the grenade is to be armed or inspected, as described above.

The plane portion 20 of the piece of sheet metal is pro- "vided on eachside of the firing pin 3 with a groove 27. One of the grooves 27 forms asupport for one end 10 of the screw spring 9, while the other groove 27forms a space for the other end 11 of the spring 9, which end engageswith the frame 7. The grooves 27 are formed by bending or pressing ofthe plane portion 20, whereby bulges 28 are formed in the side of theplane portion 20 which is remote from the grooves 27. These bulges 28are arranged to come down against the top of the detonator 4 when thefiring pin 3 strikes the primer 5. This ensures that the plane portion20 cannot prevent the gases from flowing out from the detonator afterthe time fuse 29 therein has been ignited.

The embodiment according to Fig. 2 differs from the one shown in Fig. 1only in that it is provided with an additional safety means. Thisconsists of a member 30 formed of a metal sheet or the like which ispivotally mounted at its upper right hand corner (as seen in Fig. 2)upon the handle 12. When the grenade is secured by the said additionalsafety means, notches 31 in the member 30 engage with projections 32 onthe frame 7 so that the handle 12 cannot swing around its end 13 and socannot be removed from the hand grenade 1. In this position a leafspring 33 on the member 30, which is provided with a thumb grip 34,engages with the end 13 of the handle 12. The additional safety means isreleased by the member 30 being swung around its upper right cornerpivot by means of thumb pressure applied at 34 against the action of theleaf spring 33, so that the notch 31 no longer engages with theprojections 32. The said additional safety means may consequently besecured or released quite easily by means of the throwing hand.

In the secured or cocked position the parts occupy the position shown inFig. 1. After the safety needle 15, including leg 15', has been removedand the additional safety means has been released, the hammer 6 tends tomove the handle 12 aside through the action of the firing pin springpressing the legs or extensions 21 of cock 6 against the inner side ofhandle 12, so that the hammer by the throwing hand against the handgrenade 1. When: the grenade 1 is released from the hand, the handle 12is turned by the hammer 6 about the projection14, then handle 12 swingsclear, and hammer 61 swings firing pin 3' so as to strike the primer.When the handle 12' turns, the legs or extensions 21 engage therewithall the time, for which reason the firing pin 3 cannot touch handle 12and therefore is not deformed when it strikes the primer 5'.

As appears from the drawings, the legs 21 extend a substantial distancefrom the shaft 8, which ensures that the legs 21 throw the handle 12from the hand grenade when the grenade is thrown.

.The invention is not restricted to the embodiments described above andshown in the drawings but may be varied in numerous ways within thescope of the appended claim. 7

What I claim and desire to secure by Letters Patent is: A firingmechanism for a grenade, said grenade comprising a detonator having anouter end portion with a primer therein, comprising a frame on saidgrenade, pivot means on said frame, a hammer rotatably mounted on saidpivot means, a firing spring mounted between said frame and said hammerand urging said hammer to rotate around said pivot means toward saidouter end portion of said detonator, a safety handle having a safetyposition engaging said hammer to hold it in a cocked position away fromsaid detonator, said hammer having a fired position disengaged from saidhandle and engaging said outer end portion of said detonator, a firingpin on said hammer engaging said primer in said fireduposition, saidhammer comprising a pair of spaced parallel legs joined by a crosspiecespaced from said pivot means, said firing pin; 136mg? on saidcrosspiece, said legs having hammer, extensions which extend beyond saidfiring pin on the" side thereof opposite said pivot'means, said handlehaving a hook portion detachably engaging said frame in said safetyposition, said hammer. extensions engaging said safety handle in thisposition to apply an outward force to said handle for swinging thelatter around its hook portion without said handle contacting saidfiring pin.

ReferencesCited in: the file ofi this patent r FOREIGN-PATENTS GreatBritain Sept: 1,1954

